A variety of different metal complexes have shown utility in effecting the copolymerization of epoxides and carbon dioxide to form aliphatic polycarbonates (APCs), including complexes based on zinc or aluminum salts, double metal cyanide complexes, and more recently, those based on transition metal coordination complexes (e.g., porphyrin complexes, salen complexes, etc.). The latter type provides several advantages, including the production of polycarbonates having a high carbonate content, easier catalyst preparation, and decreased induction time prior to polymerization. However, some of these catalysts have a tendency to become bound to the polymer chain during polymerization, which can complicate separation of the catalyst from the polymer product. Therefore, there remains a need for the continued development of novel metal complexes that have improved reaction and/or product purity characteristics.